Cholinesterase Enzymes Inhibitors from the Leaves of Rauvolfia Reflexa and Their Molecular Docking Study

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Anti-malarial Activity of Isoquinoline Alkaloids from the Stem Bark of Actinodaphne macrophylla

Seven isoquinoline alkaloids isolated from the bark of Actinodaphne macrophylla in this study demonstrated in vitro antiplasmodial activities against Plasmodium falciparum 3D7 with IC50 values of 0.08 μM, 0.05 μM, 1.18 μM, 3.11 μM, 0.65 μM, 0.26 μM, and 1.38 μM for cycleanine, 10-demethylxylopinine, reticuline, laurotetanine, bicuculine, α-hydrastine and anolobine, respectively, which are comparable with the reference standard, chloroquine. 10-Demethylxylopinine was found to be the most active of these compounds

Cholinesterase Enzymes Inhibitors from the Leaves of Rauvolfia Reflexa and Their Molecular Docking Study

Plants of the Apocynaceae family have been traditionally used in the treatment of age-related brain disorders. Rauvolfia reflexa, a member of the family, has been used as an antidote for poisons and to treat malaria. The dichloromethane, ethanol and methanol extracts from the leaves of Rauvolfia reflexa showed potential acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory activities, with IC50 values in the 8.49 to 52.23 g/mL range. Further cholinesterase inhibitory-guided isolation of these extracts afforded four bioactive compounds, namely: (E)-3-(3,4,5-trimethoxyphenyl)acrylic acid (1), (E)-methyl 3-(4-hydroxy-3,5-dimethoxyphenyl) acrylate (2), 17-methoxycarbonyl-14-heptadecaenyl-4-hydroxy-3-methoxycinnamate (3) and 1,2,3,4-tetrahydro-1-oxo-β-carboline (4). The isolated compounds showed moderate cholinesterase inhibitory activity compared to the reference standard, physostigmine. Compounds 1 and 2 showed the highest inhibitory activity against AChE (IC50 = 60.17 µM) and BChE (IC50 = 61.72 µM), respectively. Despite having similar molecular weight, compounds 1 and 2 were structurally different according to their chemical substitution patterns, leading to their different enzyme inhibition selectivity. Compound 2 was more selective against BChE, whereas compound 1 was a selective inhibitor of AChE. Molecular docking revealed that both compounds 1 and 2 were inserted, but not deeply into the active site of the cholinesterase enzymes

New Indole Alkaloids from the Bark of Rauvolfia Reflexa and their Cholinesterase Inhibitory Activity

Background/Aims: Rauvolfia reflexa is a member of the Apocynaceae family. Plants from the Apocynaceae family have been traditionally used in the treatment of age-related brain disorders Methods and Results: Two new indole alkaloids, rauvolfine C (1) and 3-methyl-10,11-dimethoxy-6-methoxycarbonyl-β-carboline (2), along with five known, macusine B (3), vinorine (4), undulifoline (5), isoresrpiline (6) and rescinnamine (7) were isolated from the bark of Rauvolfia reflexa. Cholinesterase inhibitory assay and molecular docking were performed to get insight of the inhibitory activity and molecular interactions of the compounds. The compounds showed good to moderate cholinesterase inhibitory activity with IC50 values in the range of 8.06 to 73.23 µM. Compound 7 was found to be the most potent inhibitor of both acetylcholinesterase (AChE) and butyrylcholinesterase (BChE). Compounds 1, 2, 5 and 6 were found to be selective towards BChE, while compounds 3, 4 and 7 were dual inhibitors, having almost equal inhibitory activity on both AChE and BChE. Molecular docking revealed that compounds 6 and 7 interacted differently on AChE and BChE, by means of hydrophobic interactions and hydrogen bonding. In AChE, the indole moiety of both compounds interacted with the residues lining the peripheral anionic site, whereas in BChE, their methoxy groups are primarily responsible for the strong inhibitory activity via interactions with residues at the active site of the enzyme. Conclusion: Two new and five known indole alkaloids were isolated from R. reflexa. Among the compounds, 7 and 6 showed the most potent and promising cholinesterase inhibitory activity, worthy for further investigations

Anti-malarial Activity of Isoquinoline Alkaloids from the Stem Bark of <i>Actinodaphne macrophylla</i>

Seven isoquinoline alkaloids isolated from the bark of Actinodaphne macrophylla in this study demonstrated in vitro antiplasmodial activities against Plasmodium falciparum 3D7 with IC50 values of 0.08 μM, 0.05 μM, 1.18 μM, 3.11 μM, 0.65 μM, 0.26 μM, and 1.38 μM for cycleanine, 10-demethylxylopinine, reticuline, laurotetanine, bicuculine, α-hydrastine and anolobine, respectively, which are comparable with the reference standard, chloroquine. 10-Demethylxylopinine was found to be the most active of these compounds. </jats:p

Annona muricata (Annonaceae): A Review of Its Traditional Uses, Isolated Acetogenins and Biological Activities

Annona muricata is a member of the Annonaceae family and is a fruit tree with a long history of traditional use. A. muricata, also known as soursop, graviola and guanabana, is an evergreen plant that is mostly distributed in tropical and subtropical regions of the world. The fruits of A. muricata are extensively used to prepare syrups, candies, beverages, ice creams and shakes. A wide array of ethnomedicinal activities is contributed to different parts of A. muricata, and indigenous communities in Africa and South America extensively use this plant in their folk medicine. Numerous investigations have substantiated these activities, including anticancer, anticonvulsant, anti-arthritic, antiparasitic, antimalarial, hepatoprotective and antidiabetic activities. Phytochemical studies reveal that annonaceous acetogenins are the major constituents of A. muricata. More than 100 annonaceous acetogenins have been isolated from leaves, barks, seeds, roots and fruits of A. muricata. In view of the immense studies on A. muricata, this review strives to unite available information regarding its phytochemistry, traditional uses and biological activities